Alkoxysulfidosilane compounds are used in the manufacture of tires as coupling agents, The alkoxysulfidosilane compounds couple fillers into the rubber, reducing the amount of filler required in the tire formulation and improving the performance of the resulting rubber. This invention pertains to the process of manufacturing haloalkylalkoxysilanes, which are key intermediates in the production of alkoxysulfidosilanes.
The production of haloalkylalkoxysilanes is documented in the literature. One means of producing a haloalkylalkoxysilane is through the hydrosilation of an alkenylchloride compound, such as allyl chloride, in the presence a catalyst. Some catalysts that can promote these hydrosilation reactions comprise compounds containing platinum, rhodium, or iridium, For instance, platinum containing hydrosilation catalysts and their use are disclosed in U.S. Pat. Nos. 2,823,218, 3,814,730, 3,715,334, 3,516,946, 3,474,123, 3,419,593, 3,220,972, 3,188,299, 3,178,464, 3,159,601, German Patent No. 1,165,028 and published U.K. Patent Application No. 2,019,426A. Hydrosilation over chloro-rhodium compounds is disclosed in U.S. Pat. Nos. 3,296,291 and 3,564,266; and, hydrosilation over iridium compounds has been disclosed in U.S. Pat. No. 4,658,050, U.S. Pat. No. 6,359,161, U.S. Pat. No. 6,388,119 US 2006/0167296, U.S. Pat. No. 5,616,762, US 2005/0240043, JP2768159, JP2938731 WO 2004/113354, and WO 2003048169.
The present inventors have found that certain iridium compounds, when used according to the process of the invention, generate haloalkylhalosilanes and haloalkylalkoxysilanes in good yields. The present inventors have also found that, in contrast to platinic catalysts, by restricting the exposure of iridium catalysts to oxygen, the activity of the catalyst can be improved and/or prolonged.